RE: [PATCH] Support logic shift left/right for avx512 mask type.

[Richard Biener <rguenther@suse.de>]

On Thu, 22 Jul 2021, Liu, Hongtao wrote:

> 
> 
> >-----Original Message-----
> >From: Uros Bizjak <ubizjak@gmail.com>
> >Sent: Wednesday, July 21, 2021 4:23 PM
> >To: Hongtao Liu <crazylht@gmail.com>
> >Cc: Liu, Hongtao <hongtao.liu@intel.com>; gcc-patches@gcc.gnu.org; H. J. Lu
> ><hjl.tools@gmail.com>; Richard Biener <rguenther@suse.de>
> >Subject: Re: [PATCH] Support logic shift left/right for avx512 mask type.
> >
> >On Wed, Jul 21, 2021 at 5:05 AM Hongtao Liu <crazylht@gmail.com> wrote:
> >>
> >> On Tue, Jul 20, 2021 at 9:41 PM Uros Bizjak <ubizjak@gmail.com> wrote:
> >> >
> >> > On Tue, Jul 20, 2021 at 2:33 PM liuhongt <hongtao.liu@intel.com> wrote:
> >> > >
> >> > > Hi:
> >> > >   As mention in
> >> > > https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575420.html
> >> > >
> >> > > ----cut start-----
> >> > > > note for the lowpart we can just view-convert away the excess
> >> > > > bits, fully re-using the mask.  We generate surprisingly "good" code:
> >> > > >
> >> > > >         kmovb   %k1, %edi
> >> > > >         shrb    $4, %dil
> >> > > >         kmovb   %edi, %k2
> >> > > >
> >> > > > besides the lack of using kshiftrb.  I guess we're just lacking
> >> > > > a mask register alternative for
> >> > > Yes, we can do it similar as kor/kand/kxor.
> >> > > ---cut end--------
> >> > >
> >> > >   Bootstrap and regtested on x86_64-linux-gnu{-m32,}.
> >> > >   Ok for trunk?
> >> > >
> >> > > gcc/ChangeLog:
> >> > >
> >> > >         * config/i386/constraints.md (Wb): New constraint.
> >> > >         (Ww): Ditto.
> >> > >         * config/i386/i386.md (*ashlhi3_1): Extend to avx512 mask
> >> > >         shift.
> >> > >         (*ashlqi3_1): Ditto.
> >> > >         (*<insn><mode>3_1): Ditto.
> >> > >         (*<insn><mode>3_1): Ditto.
> >> > >         * config/i386/sse.md (k<code><mode>): New define_split after
> >> > >         it to convert generic shift pattern to mask shift ones.
> >> > >
> >> > > gcc/testsuite/ChangeLog:
> >> > >
> >> > >         * gcc.target/i386/mask-shift.c: New test.
> >
> >
> >+(define_insn "*lshr<mode>3_1"
> >+  [(set (match_operand:SWI12 0 "nonimmediate_operand" "=<r>m, ?k")
> >+    (lshiftrt:SWI12
> >+      (match_operand:SWI12 1 "nonimmediate_operand" "0, k")
> >+      (match_operand:QI 2 "nonmemory_operand" "c<S>, <KS>")))
> >+   (clobber (reg:CC FLAGS_REG))]
> >+  "ix86_binary_operator_ok (LSHIFTRT, <MODE>mode, operands)"
> >
> >Also split this one to QImode and HImode to avoid conditions in isa attribute.
> >
> >OK with this change.
> >
> 
> Thanks for the review, here's the patch I'm check in.

Works with my experimental patches, thanks!

Richard.